1. Field of the Invention
The invention relates to an economically feasible procedure for extracting protein from pork bones to produce a usable end product solution containing a desirable protein concentration. More particularly the invention relates to critical controls that must be exercised in the batch treatment of pork bones to stop denaturing of the pork protein which if not stopped may destroy the usability of the batch solution.
Further, the invention relates to a procedure for extracting protein from pork bones involving batch cooking and processing of the general type heretofore successfully used for extracting protein from beef bones as described in U.S. Pat. No. 4,176,199; but which known procedure is modified to include critical controls which prevent frequent unpredictable production of an unusable end product solution when using the method of said U.S. Pat. No. 4,176,199.
2. Description of the Prior Art
The economically successful method of extracting protein from beef bones set forth in said Patent No. 4,176,199 was initially believed to be applicable to protein extraction from pork bones. However, unpredictable complete failures were encountered in numerous attempts to use this prior batch beef bone protein extraction procedure or treatment in processing pork bones.
Very occasionally such prior art treatment of one batch of pork bones unaccountably turned out to be favorable. Nevertheless numerous attempts to repeat such occasional favorable results ended in failure, and in complete loss of many, many batches of treated pork bones and cooked solution. The protein solution or soup or broth end product was not usable for flavoring or protein supplement purposes. This led to extended efforts during a long time period to solve the problem.
The problem is believed to have existed for many reasons, among others, because there are many different proteins in animal bodies. They differ from animal to animal of the same kind, and in animals of different kinds such as cattle and pigs. They also differ in any animal with age change.
Further, any procedure for extracting protein from animal bodies involves complex chemical reactions. This complexity increases where the differences noted are involved.
We have discovered that freshness or stable condition of the protein content of pork bones maintained refrigerated after packing house deboning is exeedingly short, not more than two to three days. Lack of freshness of pork bones treated may contribute to the problem. Freshness from the standpoint of protein extraction from beef bones is not materially changed over a period of from five to seven or more days when the beef bones are refrigerated.
A further discovery in attempts to solve this problem is that portions of the prior beef bone cooking procedure from the beginning of batch treatment until the cooked soup mixture is filtered and screened to separate liquid from solids must be altered, to successfully extract protein from batch to batch of pork bones, and so as not to produce a protein solution end product which for all practical purposes is worthless because of odor and taste.
This alteration in the prior beef bone treatment procedure involves several related controls, the first of which relates to the heating cycle wherein after heating for approximately 3 to 31/2 hours in the range of 135.degree. F. to 145.degree. F. the aqueous pork bone-enzyme-NaCl mixture is heated rapidly in about 10 minutes to 195.degree. F. as in one example in the prior beef treatment.
After such heating cycle proceeds with heating the mixture at 195.degree. F., but not above that temperature, for 1/2 hour, a radical change in temperature control involves extremely rapidly chilling the mixture or cooked soup stock down to 150.degree. F. as quickly as possible.
The rapid chilling step at the end of the cooking process is necessary to prevent continuing denaturing of the pork protein, which appears to happen much more rapidly with pork bones rather than beef bones. The cooking process has taken the pork protein to the soluble stage, but any further denaturing above 150.degree. F. extends the reaction past the soluble protein state and apparently forms one or more of peptides, polypeptides or peptones.
Accordingly, there is an existing need for an economically feasible and successful procedure for extracting valuable protein from pork bones which may be used as a flavoring agent or a protein supplement in a protein solution having a desired or required degree of protein concentration.